Conveying apparatus



Nov. l0, 1953 F. w. wEHMxLLER CONVEYING APPARATUS 3 Sheets-Sheet l Filed001'.. 26 1949 ATTORNEY.

Nov. l0, `1953 F. w. WEI-:MILLER CONVEYING APPARATUS 3 Sheets-Sheet 2Filed Oct. 26 1949 INVENTOR. minimo w. WEHWLLER BY CUULW# gmbh@ATTORNEY.

Nov. 10, 1953 F. w. wEHMlLLx-:R 2,658,508

CONVEYING APPARATUS Filed Oct. 26, 1949 3 Sheets-Sheet 3 F KG 5,

MPTY @RATE and B Patented Nov. 10, 1953 UNITED STATES PATENT FFICEBarry-Webmiller Machinery Company,

Louis, Mo., a corporation of Missouri Application Getober 26, 1949,Serial No. 1i-2 ',56'2

9 Claims. l

This invention relates to conveying apparatus of the type wherein a pairof load-carrying grates are recprocated in cyclic paths to impart a stepby step movement to the load. The grates are alternately raised andlowered to repeatedly transfer the load from one grate to the other. Theloaded grate moves forwardly at a relatively high elevation to advancethe load, while the empty grate moves rearwardly in a lower plane. Atthe end of each step, the empty grate moves upwardly to receive theload, and its companion grate then moves downwardly to an idle positionWhere it moves rearwardly while the loaded grate moves forwardly.

Conveyors of this type are. advantageously employed to graduallytransmit extremely heavy loads through various kinds of treating zones.For example, the contents of numerous traveling bottles, jars or cansmay be subjected to temperature-changing processes for pasteurization, l

pasteurizing art, wherein 5 tons may be regarded .ii

as a medium load. Conveyors of this type are also desirable for thetransmission of considerablyV heavier articles which subject the gratesto much heavier loads.

An object of the present invention is to provide ample clearance betweenthe top surface of a loaded grate and the top surface of a lower emptygrate while said grates are moving longitudinally in oppositedirections, and also to materially reduce the power requirements when itbecomes necessary to lift a loaded grate during the frequency operationsof transferring the heavy load from a descending grate to a risinggrate.

More specifically stated, an object of the invention is to providehighly ecient leverage during a transfer period in which lifting poweris required for a loaded grate, and at the same time cause a fallinggrate to serve as a counterbalance which aids in lifting the load. Afurther object is to cause a falling loaded grate to aid in lifting theempty grate.

A highly desirable form of the invention ac complishes all of theseresults under conditions wherein the loaded grate falls a very slightdistance during a period of time in which the empty grate rises a muchgreater distance to receive the descending load;

With the foregoing and other objects in view, the invention comprisesthe novel combination (Cl. 198.--2l9) 2: and arrangement of detailsherein disclosed to illustrate one form of the invention. However, it isto be understood that the scope of the invention extends to numerousvariations and modications described by terms employed inthe claimshereunto appended.

Fig. 1 is a diagrammatical top or plan view of a conveyor embodyingfeatures of the invention, middle portions of the grate structure beingbroken away,

Fig. 2 is a side view of the aparatus shown in Fig. l.

Fig. 3 is an end view, drawn to. a larger scale.

Fig. 4 is an enlarged vertical section on the line fi-i in Fig. 1.

Fig. 5 is a diagram illustrating upward and downward movements whichoccur in transferring the load from one grate to another.

Fig. 6 is a similar diagram illustrating subsequent upward and downwardmovements which occur after the load has been transferred.

rlhe conveyor shown in the drawings. includes a pair of grates A and Bon which the load is alternately supported and advanced step by step, aswill be hereafter described.

rThe grate A comprises a pair of longitudinal side beams l', transversesuports 8 having their ends secured to said side beams, transversestrips Si in the form of combs secured to said transverse supports ii,and a group of elongated loadreceiving grate bars iii carried by saidtransverse strips 9.

The companion grate B likewise consists of a pair of longitudinal sidebeams ii, transverse supports i2 having their ends secured to the beamsil, transverse strips i3 secured to said supports I2, and a group ofelongated load-receiving grate bars iii.

As shown most clearly in Figures 2 and 3, the load-receiving bars ld ofgrate A and the similar bars lli of grate B are alternately arrangedwith respect to each other. in these views, the grate bars iii occupyelevated positions, so that the load can be carried on the top surfacesof said bars it, while the corresponding bars lli of the grate B occupylower positions entirely below the load. Under these conditions, theelevated bars I8 can be moved forwardly to advance the load, While thelower bars I4 move rearwardly in a return step of their cycle.

The elevated grate bars I0 in Figures 1 and 3 are supported by thetransverse strips 9'. However, each of said strips S is provided withelongated slots l5 (Fig. 3) to idly receive the lower grate bars lli. Inother words, the grate bars I are carried by the transverse strips 9,while the grate bars I4 are independently supported by correspondingtransverse strips I3, so that each grate can occupy an elevated positionwhile its companion grate occupies a lower position. In the apparatusshown in the drawings, the side beams 'I of the grate A are seated onrollers I6, and the side beams II of grate B are supported on similarrollers I'I, so as to reduce frictional resistance in moving the grates.

Attention is now directed to a means for reciprocating the grates onsaid rollers I and I1. A driving arm I8 extends downwardly from one endof a transverse shaft I9, as shown in Figures 2 and 3, said shaft beingprovided with arms 2 connected by means of links 2l to the side beams II of the grate B. It is to be understood that an oscillatory movementmay be imparted to the shaft I9 and its arms 20, so as to transmitmovement through the links 2 I, thereby reciprocating the side beams IIof grate B on the rollers I1.

The side beams 'I of grate A are likewise adapted to reciprocate on therollers I6. As shown in Figures l, 2 and 3, each side beam 'i isconnected by means or" a link 22 to the upper end of an arm 23 carriedby a transverse shaft 2d. Each arm 2e is provided with gear teethmeshing with teeth on an arm 23, as shown at 25 in Figures and 3.Therefore, when the driving arm i3 is moved in an arc of a circle, thecompanion arms 2l and 23 (Fig. 2) will move in opposite directions,thereby causing the grates A and B to move longitudinally in oppositedirections.

As a suitable means for transmitting power to the driving arm I8, Fig.l, diagrammatically shows a cylinder 2S containing a piston 2"!connested to said arm I8. Fluid under pressure may be admitted to anddischarged from the cylinder 26 through the medium of any suitableautomatic valve device, so as to impart intermittent movements to thedriving arm I3. This arm is moved in one direction to impart forwardmovement to elevated grate bars IE! of the grate A, so as to advance theload one step, while imparting rearward movement to the lower grate barsIii of the grate B. Thereafter, in a manner to be hereafter described,the grate bars I9 are lowered and the grate bars ifi are elevated,thereby transferring the load from the grate A to the grate B. Thedriving arm IS (Fig. 1) is then actuated to impart forward movement tothe elevated grate bars while imparting rearward movement to the lowergrate bars. The grates A and B are thus reciprocated in cyclic paths toimpart a step by step movement to the load.

Figures 2, 4, and 6 illustrate a specific embodiment of the novel meansfor raising and lowering the grates to repeatedly transfer the load fromone grate to another. In this form of the invention, a group ofoscillatory levers is employed, each lever comprising a pair ofsupporting arms 28 and 2G integrally united with each other, and anoperating arm 3i) united with said pair of supporting arms. The rollersIii form parts of the arms 28, while the rollers I'I likewise form partsof the supporting arms 29. Each of these peculiar levers is carried by atransverse shaft 3l having its end portions mounted in stationarybearings 32. The rollers I; at the upper ends of the lever arms 23 liebelow and form seats for the side beams a of grate A, while the similarrollers I'I of arms 29 lie below and provide seats for the side beams II of the grate B.

As shown in Figures 2 and 5 the companion lever arms 2S and 29 arelocated at an angle to each other, so that the top of one lever arm canoccupy an elevated position While the top of its companion arm is in alower position. The grate A can be supported in an elevated position onthe rollers i6, while the grate B is supported in a lower position onthe rollers i'I, as shown by full lines in Figures 2, Ll and 5. However,the lever arms 2S and 29 can be moved to the positions shown by fulllines in Fig. 6 so to lift the grate B to its elevated position whilelowering the grate A to an idle position.

As a diagrammatical illustration of a suitable means for simultaneouslyoperating all of the lever arms 28 and 29, Fig. 2 shows a cylinder 33provided with a piston E4, and piston rods 35 connected to operatingarms 3-, the latter being secured to the transverse shafts 3i. Anysuitable automatic regulating means may be employed to control theadmission and discharge of fluid at the cylinder 33, so as to move thelever arms 28 and 29 at regular intervals. These arms are to be actuatedat the end of each feeding step of the conveyor, so as to lower a loadedgrate and at the same time raise an empty grate, thereby transferringthe load from one grate to another.

Attention is now directed to highly advantageous leverage conditions andvarying changes in speed, coupled with desirable counterbalancinginvolved in raising and lowering the grates.

Assuming that the supporting rollers I5 and il are located in thepositions shown by full lines in Fig. 5 while the elevated grate A movesin the direction of arrow 3S to advance the load, and the lower emptygrate B moves rearwardly as indicated by arrow 3l. During this period,the lever arms 28 and 29 are stationary. However, at the end of eachfeeding step, said lever arms 2S and 29 are moved in arcuate paths aboutthe axis of their shaft, or fulcrum 3i, while the grates move invertical directions quite different from said arcuate paths. By unitingthe lever arms 28 and 29, and separating them from each other in theirarcuate paths, said lever arms can be moved at a uniform speed, with theresult of moving the companion grates at very favorable non-uniformspeeds.

For example, during the initial stage of their movement, said lever armsand their rollers It and I'I are shifted from the positions shown byfull lines in Fig. 5 to the positions shown by dotted lines, so as totransfer the load from the grate A to the rising empty grate B. Study ofFig. 5 will show that the rollers I and I'i move simultaneously at thesame speed, and in the same direction in their arcuate paths whilepassing from the positions shown by full lines to the positions shown indotted lines. However, this movement of roller I6 allows the loadedgrate to descend only a very slight distance, while the movement ofroller I? causes the empty grate to rise a much longer distance. Therollers then lie in approximately the same horizontal plane, so as tolocate the grate B in a load-receiving position wherein its top surfaceis approximately ush with the top surface of the grate A. From thiscondition, shown by dotted lines in both Fig. 5 and Fig. 6, the leverarms 2S and 29 continue in motion to the positions shown by -full linesin Fig. 6, thereby lifting the load on grate B a very slight distance,while the unloaded grate A descends a much greater distance, so as toprovide the desired clearance between the top E surface of the emptygrate and the top surface of the leaded grate.

During all of these movements, the load falls and rises a very slightdistance, for example onesixteenth of an inch. Therefore, a relativelylow degree of power is required for the operation of lifting the load.Furthermore, during this lifting movement, the power is transmitted fromthe roller il as it moves a relatively long distance, from midwayposition shown by dotted lines in Fig. 6 to its highest position shownby full lines. This results in extremely favorable leverage during theperiod in which power is required to lift the load, the lever arm 2i!(Fig. 5) being moved a relatively long distance to lift the load a veryslight distance.

Additional important advantages appear in the manner in which the unitedlever arms 28 and 29 cooperate to provide power-saving counterbalances.During the rlrst half of the movements illustrated by Figures 5 and 6,the rollers l@ and il move from extreme positions shown by full lines inFig. 5 to midway positions shown by dotted lines, so as to lower theload on grate A while lifting the empty grate B. At this time thedescending heavy load on grate A tends to impart downward movement tothe roller I9 of the lever arm 2S. This downward thrust at lever arm 28tends to elevate its companion lever arm 2S, thereby imparting an upwardthrust to the roller il below the rising empty grate B. The united leverarms 23 and 29 are thus employed to provide a counterbalance wherein thefalling load tends to lift the rising empty grate.

Furthermore during the subsequent operation of lifting the load, whenthe rollers i9 and il move from midway positions shown by dotted linesin Fig. 6 to extreme positions shown by full lines in the same view, thefalling empty grate A imparts a downward thrust to the roller Iii,tending to force said roller downwardly from the position shown bydotted lines to the position shown by full lines in Fig. 6. Thisdownward thrust is imparted to the lever arm 28, and transmitted to thecompanion lever arm 29, so as to aid in moving said arm 29 and itsroller il to positions shown by full lines in Fig. 6. The weight of thefalling empty grate A on the roller i9 is thus employed to aid inlifting the loaded grate B.

The value of such counterbalancing is improved by the specificarrangement of the united lever' arms 29 and 29. For example, in Fig. 6the empty grate A falls a relativelylong distance on the roller i9,while the loaded grate B rises a very slight distance on the roller il'.Under these specinc conditions there is a very favorable leverage factorin the transmission of power from the falling empty grate to the risingloaded grate. A similar favorable condition appears in thecounterbalancing suggested by Fig. 5, wherein the loaded grate A falls avery slight distance to aid in lifting the empty grate B a much greaterdistance.

In Figures 5 and 6 the transferring operations begin when the lever arms28 and 29 are located in extreme positions shown by full lines in Fig. 5and conclude by locating said arms in the eX- treme positions shown byfull lines in Fig. 6. However, the same kind of transferring conditionswill be obtained when said lever arms are moved reversely from theextreme positions of Fig. 6 to the extreme positions of Fig. 5. lt willbe observed in Fig. 5 that the vertical lever arm 29 extends upwardlyfrom the horizontal axis of the fulcrum 3i which lies below the grates,the

roller I6 beingv in a dead center position directly above said axis,while the companion lever arm 29 and its roller l1 occupy lowerpositions at the right side of the vertical arm 28. These extremepositions of Fig. 5 are to be compared with the opposite extremepositions of Fig. 6, wherein the arm 29 occupies the vertical positionwhile the arm 28 and its roller I6' occupy lower positions at the leftof said vertical arm 29. Therefore, during the next transferringoperation, which occurs after the load has been advanced one step on thegrate B, the lever arms 28 and 29 can be moved back from the extremepositions. shown by full lines in Fig. 6 to the opposite extremes shownby full lines in Fig. 5 to obtain the same values in the transmission ofpower and counterbalancing as previously described in referring to thesediagrams.

The arcuate strokes of the companion lever arms 28 and 29 are uniform inlength, and when said arms are arranged as herein shown the total upwardmovement of a grate is equal to the total downward movement of itscompanion grate. It may be noted that this desirable equalization isobtained despite the fact that the grates are deliberately movedsimultaneously a different speeds to obtain several highly importantadvantages.

Figures 5 and 6 show only one pair of the lever arms 29 and 29. However,it will be understood that there are several pairs located below thegrates A and B, and movable simultaneously in the manner described inreferring to Figures 5 and 6. Any suitable operating means may beemployed to move these companion lever arms, so as to transfer the loadfrom one grate to another at the end of each feeding step of theconveyor.

I claim:

l. In a conveyor, a` pair of load-carrying grates adapted to reciprocatein cyclic paths to impart a step by step movement to the load, and meansfor raising and lowering said grates to transfer the load from one grateto the other, the load being transfered from a descending grate to anempty rising grate, said raising and lowering comprising a plurality ofoscillatory supportsy for said grates, each of said oscillatory supportsincluding a pair ofl seats united with each other so as to oscillatesimultaneously, one seat of each pair being a support for one of saidgrates, while the other seat of the same pair forms a support for theother grate, the seats of each pair being separated from each other intheir arcuate lines of oscillation, so that when one seat occupies anelevated position the companion seat of the same pair is in a lowerposition, and means for oscillating all of said oscillatory supports andhence all of said pairs of seats in their arcuate paths to lower theelevated seats and thereby lower the elevated grate, while raising theother seats to elevate the other grate, the united seats of each pairbeing moved simultaneously in their arcuate paths so as to impart acomparatively rapid initial upward movement to the rising empty grate,while impartingl a relatively slow initial downward movement to theloaded grate, thereby transferring the load during said initial downwardmovement of the loaded grate.

2. in a conveyor, a pair of load-carrying grates adapted to reciprocatein cyclic paths to impart a step by step movement to the load, and meansfor raising and lowering said grates to transfer the load from one grateto the other, the load being transferred from a, descending grate to anempty risingggrate, said raising and lowering means comprising a groupof oscillatory levers supporting said grates, each of said oscillatorylevers being movable about a substantially hori- Zontal axis andincluding a pair of seats united with each other so as to oscillatesimultaneously about said axis, one seat of each pair being a supportfor one of said grates, while the other seat of the same pair forms asupport for the other grate, the seats of each pair being located at thesame side of said axis in an angularly separated relation, so that whenone seat occupies its elevated position the companion seat of the samepair is in an angularly spaced lower position, and means for oscillatingall of said levers in their arcuate paths to lower the elevated seatsand thereby lower the elevated grate, while raising the other seats toelevate the other grate, the united seats of each pair being movedsimultaneously and at the same speed in their arcuate paths so as toimpart a comparatively rapid initial upward movement to the rising emptygrate, while imparting a relatively slow initial downward movement tothe loaded grate, thereby transferring the load during the initialdownward movement of the loaded grate.

3. In a conveyor, -a pair of load-carrying grates adapted to reciprocatelongitudinally in cyclic paths to impart a step by step movement to theload, and means for raising and lowering said grates to transfer theload from one grate to the other, the load being transferred from adescending grate to an empty risingl grate, said raising and loweringmeans comprising a plurality of lever arms supporting said grates, saidlever arms being arranged in pairs with the arms of each pair integrallyformed and located at an acute angle to each other, so that the top ofone lever arm of each pair occupies its elevated position while the topof its companion lever arm is in f.

a lower position angularly spaced therefrom, the top of one lever arm ofeach pair being located below one of said grates to form a supporttherefor, while the top of the other lever arm of the same pair liesbelow and forms a support for the y.

other grate, and means for oscillating all of said pairs of lever armsin arcuate paths to lower the elevated arms along an arcuate path andtherebyl drop the elevated grate, while raising the other arms along anarcuate path to elevate the other grate, the integral lever arms of eachpair being moved simultaneously in the same direction and at the samespeed, so as to impart the counterweight effect of the loaded grate onthe initial upward movement of the empty rising grate, and to impart thecounterweight effect of the empty grate upon the rising loaded gratemovement.

4. In a conveyor, a pair of approximately horizontal load-carryinggrates adapted to reciprocate in cyclic paths to impart a step by stepmovement to the load, and means for raising and lowering said grates totransfer the load from one grate to the other, the load beingtransferred from a descending grate to an empty rising grate, saidraising and lowering means comprising a plurality of lever armssupporting said grates, said lever arms being arranged in pairs with thearms of each pair integrally formed and located at an angle to eachother, so that the top of one lever arm of each pair occupies itselevated substantially vertical position while the top of its companionlever arm is in an angularly spaced lower position, the top of one leverarm of each pair being provided with a roller located below one of saidgrates to form a seat therefor, while the top of the other lever arm ofthe same pair is provided with a roller located below and forming a seatfor the other grate, and means for oscillating all of said pairs oflever arms in arcuate paths to lower the elevated arms and thereby dropthe elevated grate, while raising the other arms toward a substantiallyvertical position to elevate the other grate, the integral lever arms ofeach pair being moved simultaneously so as to impart a comparativelyrapid initial upward movement to the empty rising grate, while impartinga relatively slow initial downward movement to the loaded grate, therebytransferring the load during said initial downward movement of theloaded grate.

5. In a conveyor, a pair of approximately horizontal load-carryinggrates adapted to reciprocate longitudinally in cyclic paths to impart astep by step movement to the load, and means for raising and loweringsaid grates to repeatedly transfer the load from one grate to the other,the load being transferred from a descending grate to an empty risinggrate, said raising and lowering means comprising pairs of pivoted leverarms supporting said grates, the lever arms of each pair being unitedwith each other and located at an angle. tc each other at the same sideof the pivots therefor, so that the top of one lever arm of each pairoccupies an elevated substantially vertically directed position whilethe top of its companion lever arm is in an angularly spaced lowerposition, the top of one lever arm of each pair being located below oneof said grates to form a support therefor, while the top of the otherlever arm of the same pair lies below and forms a support for the othergrate, and means for pivotally oscillating all of said pairs of leverarms in arcuate paths to lower the elevated arms along arcuate paths andthereby drop the elevated grate, while raising the other arms alongarcuate paths to elevate the other grate, the integral lever arms ofeach pair being moved simultaneously in the same direction and at thesame speed, so as to impart a comparatively rapid initial upwardmovement to the empty rising grate, while imparting a relatively slowinitial downward movement to the loaded grate, the arcuate strokes ofsaid pairs of lever arms being uniform in length to equalize the upwardand downward movements of the grates, and the load-receiving topsurfaces of said grates being in approximately the same plane when saidcompanion lever arms lie midway between the ends of their arcuatestrokes.

6. In a conveyor, a pair of alternately effective load conveying gratesadapted to be reciprocated 1n raised and lowered paths to impart a stepby step movement to the load, means for alternately raising and loweringsaid grates repeatedly to transfer the load therebetween comprisingpivoted levers each having a pair of integral and angularly spaced gratesupporting arms, like arms 0f each lever supporting one of said gratesat all times in the alternate raising and lowering thereof, means forsimultaneously moving said levers alternately between a position inwhich like arms supporting one grate are in a vertically erect positionand a position in which the arms supporting the other grate are in asimilar vertically erect position, said pivoted levers alternatelypassing a position of load transfer from a loaded descending grate to anempty rising grate in which the effective travel of the descendingloaded grate is less than the effective travel of the rising empty grateto the position of load transfer, and means for reciprocating saidgrates simultaneously and in opposite directions between alternatemovements of said levers.

7. Conveying apparatus comprising a pair of grates each having aplurality of load supporting bars with the bars of said grates ininterleaved relationship and relatively movable longitudinally andtransversely of each other, lever means pivoted at one side of saidgrates opposite the load, said lever means having a pair of armsextending into supporting relation with said grates with one armsupporting one of said grates and the remaining arm supporting the otherof said grates, and means for moving said lever means angularly aboutthe pivot in opposite directions relative to a position of the levermeans wherein said arms occupy positions intermediate the limits ofangular travel of the lever means with said pair of grates insubstantially the same plane for transferring th load alternately fromone grate to the other, said pair of arms having an acute angularlyspaced relation to maintain the component of movement of said armsparallel with the length of said grate bars greater than the componentof movement of said arms transversely of said grate bar length.

8. Conveying apparatus comprising a pair of grates having interleavedload supporting bars relatively movable longitudinally and transverselyof each other, lever means pivoted at one side of said grates oppositethe load side thereof, a pair of arms on said lever means extending intograte supporting relation with one arm for one of said grates and theother arm for said other grate, and means for moving said lever means inan arcuate path to move said pair of arms in an arcuate path andalternately into positions wherein each arm moves above the other armand has a direction of motion substantially parallel with said gratewhich is supported thereby, said moving means moving said lever means ata substantially uniform speed and said pair of l0 arms having an angularspaced relation such that the linear component of movement parallel withthe longitudinal movement of said grates for each arm is always inexcess of the component of movement parallel with the transversemovement of said grates.

9. Conveying apparatus comprising a pair of elongated grates movablerelative to each other in directions parallel with the longitudinal andtransverse axes of said grates, a plurality of levers pivoted at oneside of said grates, each of said levers having a pair of angularlyspaced arms with one arm extending into supporting relation with onegrate and the other arm extending into supporting relation with theother grate, power means connected with and simultaneously oscillatingsaid levers at a uniform speed for alternately moving said gratesparallel with the transverse axes thereof whereby each grate extendsoutwardly of the other grate in alternating cycles, said arms on eachlever following arcuate paths which have components of movement parallelwith the longitudinal and transverse axes of said grates and the speedof said arms in the direction of said longitudinal componentpredominates over the speed of said arms in the direction of saidtransverse component, and separate power means connected with saidgrates for alternately moving said grates in opposite directionsparallel with the longitudinal axis of the grates between theoscillations of said levers by said rst mentioned power means.

FREDERICK W. WEHMILLER.

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